填入下面文段空白处的词语，最恰当的一组是（ ）比尔·布莱森在他的《万物简史》里介绍了超越火山的巨大破坏性。以美国为例， ① 境内有一座超级火山喷发， ② 其产生的巨大能量将摧毁数千公里范围内的所有东西，无数人会因此丧命， ③ 会导致整个国家被深达6～20米的火山灰覆盖，随后 ④ 会出现其他许多可怕后果。 ⑤ 目前人类还无法预测美国超级火山会在何时喷发， ⑥ 了解了它的杀伤力有利于我们制订各种减损预案。 ①②③④⑤⑥

The meeting is about to start, yet the speaker hasn’t turned up.— No one knows ____.

Can you tell us ___________your parents do at home.—I often do the dishes and wash the clothes.

__ the past, leaving the sadness behind, _____ you’ll see the doorof a new bright world open before you.

Jerry did research in that field for a long time.He ________ invent something useful.[ ]